.nav {
    position: fixed;
    bottom: 0;
    
    width: 100%;
    height: 0.9rem;
    border-top: 1px solid #999;
    overflow: hidden;
    background-color: #fff;
    z-index: 999;
    a {
        position: relative;
        width: 20%;
        height: 100%;
        float: left;
        color: #999;
        text-align: center;
        span {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%,-50%);
            -webkit-transform: translate(-50%,-50%);
            width: .63rem;
            height: .85rem;
            background-image: url(../img/2016_9_30_10_24_37_8593_60x800.jpg);
            background-repeat: no-repeat;
            background-size: .63rem 8.5rem;
            overflow: hidden;
        }
        .nav-home-active{
            background-position: 0 .042rem;
        }
        .nav-search{
             background-position: 0 -.85rem;
        }
        .nav-Tshirt{
             background-position: 0 -1.7rem;
        }
        .nav-shopcart{
             background-position: 0 -2.55rem;
        }
        .nav-me{
             background-position: 0 -3.4rem;
        }
    }
}